Sparking plug.



G. S. WALKER. BPABKING PLUG. APPLIoATIon FILED 220.13, 1910.

1,018,383. Patented Feb. 2o, 1912.

F/ Jr Amie/v5):

'UNITEDA STATES PATENT OFFICE.

GEORGE S. WALKER, F BOSTON, MASSACHUSETTS, ASSIGNOR 0F ONE-HALF T0 EDWARD J. CHADBOURNE, OF WAKEFIELD, MASSACHUSETTS.

SPARKING PLUG.

Specification of Letters Patent.

`Patented Feb. 20, 1912.

' cation.

This invention in sparking-plugs relate to such class ofsaid plugs as contain in their 'parts and construction, two electrodes, one more or less spherical in shape, and the other a circular running edge surrounding and spaced from said spherical electrode.

The invention consists in a combination of these two electrodes in the plug, all as hereinafter fully described.

In the accompanying drawings, forming a part of this specification, a sparking-plug of this invention is shown on an enlarged scale.

Figure 1 is a side view of the sparkingplug. Fig. 2 is a central longitudinal section. Fig. 3 is a face view at the sparkingend of the plug. Fig. 4 is a cross-section on dotted line 4-4, Fig.; 1. Fig. 5 -is an illustrative sectional view, in detail, as hereinafter appears.

'In the drawings, A is a metal tubularcasing or shell, open at both ends, and exterorly adapted, by a screw-thread a, to be screwed into and out of a suitable' female screw-threaded opening in the wall of the explosion chamber or cylinder of an internal combustion engi-ne. The shell A, intermediate of its length, has a radial circular running shoulder A2 extendingaround its inner wall.

B is a tubular plug of any suitable insulating material, such as porcelain, glass orv mica. This plug extends concentrically lengthwise of and within the shell A and at one end-portion C it terminates within and near to the smaller open and sparking-end D of the shell A. The plug B, at its other end-portion E, projects beyond the shell A and at this end-portion E is a metal screwhead or nut G. This nut'G has a depression b in its end-face toward the plug, and in this depression b is a layer o asbestos or other suitable packing, preferably soft packing. This packing b and the raised edge d surrounding the screw-nut G, ,with the screw-nut G in place, as hereinafter appears, lie against and pack the outer endface of the plug B, Fig. 2. The plug B, within the smaller tubular end-portion of the shell a, is of less external diameter than the 'internal diameter of the shell, which leaves an annular open space B2 between the plug and shell. This chamber B2 extends inwardly from the sparking end D of the shell A and ends within the larger tubular end-portion of the shell -A at the radial facetoward it of a projecting circular collar or flange H, that surrounds and is intermediate of the length of and integral with the plug B.

M is an external screw-threaded gland, screwing into the larger and screw-threaded open vend ofthe shell. A. This gland M, at its outer open end, has an internal circular running shoulder M2 that surrounds and fits the plug B, and the gland, at its inner o en end, has a sleeve 0r ring J which prefera ly closely fits and wedges within and, by one end-portion, projects from said inner open end of the gland and by that end-portion it bears against the'shoulder A2 of the shell.

In screwing the gland M into the larger open end of the shell, its inner radial shoulder M2 coming against the outer radial face of the collar H of the plug B forces said plug forward, thatis, toward the sparkingend B of the shell, and into a bearing by the inner face of its collar H against the inner end of the sleeve J, and the projecting end of the sleeve into its bearing on the shoulder A2, there securing the plug to and wit-hin the shell, and at the same time tightly closing the inner end of the annular space B2 about Vthe plug and within the shell. The plug B has an axial bore O, andk this bore extends through the whole length of the plug, and P lis a round ,metallic rod or stem, extendin loosely through said bore O, and projecting from each end thereof. This rod or stem P, at each of its projecting kend-portions, is screw-threaded, and its endfportion Q has the screw-nut G screwed on itand its then rojcting endportion beyond said nut and) also the shell A are each in suitable electric connection as common and well known. The opposite projecting end-portion R of the steni'P screws 4into a corresponding screw-threaded socket f, at the center of theflat side g ,of a inetal head S, of spherical or ball shape Afrom the shell at its remaining portion. This head S lies within and projects through the open smaller end D of the shell and its spherical portion is one of the electrodes of the sparking-plug of this invention as hereinafter fully appears.

The stem P is attached to the electrode head S by screwing it into the screwthreaded socket f of the head, and with the screw-nut G then screwed to a firm bearing against the plug B, the electrode S is brought, by its flat side g, to a bearing or seat on the end-portion E of the plug and thus the electrode S and stem P and plug B are firmly bound and secured together.

VE is the elect-rode opposed to the electrode S. This electrode V is the inner circular running edge of a flange-projection W around the opening of the end D of the shell A, and between this flange-edge or electrode 4V and the spherical-head or ele trode S is an annular open space X whic constitutes the sparkinggap, see Figs. 2, 3 and 4s Y, Y are a series of apertures or orifices at and through the shell A at-its end D, and they and the sparking-gap X open to the annular chamber or space B2 which is about the plug B and within the shell A.

It is preferable, and for the best and most satisfactory working of the sparkinglug, that the annular sparking-gap X shall e of uniform width throughout, and that the diametrical plane of the electrode S and the plane of the electrode. V, or in other Words, the circular running edge of the shell A shall be coincident. The irst, that is the securing of a sparking-gap X of uniform width' throughout, is lnsured by inserting a cylindrical tubular templet Z, with its flange Z2 at one end, all of suitable size, between said two electrodes, see Fi 5, having previously loosened screw-nut and then tightening up the screw-nut and removing the templet Z. And the second, that is, fixing the plug B in the shell A so that the diametrical plane of the spherical electrode S and that of the edge-electrode V are coincident is insured, by the use of a sleeve J, within the gland M`, of roper length, for the reason, that the lengt of the sleeve J, when the plug B is secured within the shell A, as has been explained, necessarily regulates and determines the position ofthe dia# metrical plane of the electrode S Within" and as to the electrode V.

The s arking of the plug described is at the spar 'n -gap X and as the opposed electrodes S, V are circular, obviously manyl sparking points are presented and the spark-- ing .is more. or less a continuous circle, an important advantage as is obvious.

It is plain, that, as the electrode S is secured to the plug B, the removal of the plu in no way interferes wit the described central adjustment of the electrode S on the plug. Again, that asthe positioning of the plug B within the shell A\ is regulated and determined by the sleeve J, as has been explained, the gland M and plug B can be removed and replaced at pleasure without interfering with the relative position explained of the two electrodes S and V.

In the operation of the plug the explosive gases can freely enter the chamber B2 of the shell by passing through the apertures Y and as freely pass out of said chamber. Again the contact or bearing between the shoulder M2 of the'gland M and the collar H of the plug B is preferably packed with asbestos or other suitable packing.

Having thus describe my invention what I claim and desire to secure by Letters Patent is,

l. A. sparking-plug comprising, in combination, an electrical connected metal tubular shell, exteriorly screw-threaded and. at its opposite end-portions open andvof different internal diameters joined by a circular running shoulder, and at its larger open end internally screw-threaded and at its smaller open end having a circular radial flange projecting inwardly, constituting an electrode,

a gland exteriorly screw-threaded. and

screwing into said screw-threaded end of said shell, and at one end having an internal circular running flange or shoulder and at its opposite and open end having a removable sleeve closely fitting and terminating therewithin and projecting'therefrom, an insulated cylindrical and tubular plug having an external running collar lying between said internal i'ange of, and the end of said sleeve within said gland, and at one end-portion extending into and along and spaced from 'the s maller tubular end-por tion of said shell and, said. sleeve of the gland and at its opposite end-portion projecting from said gland, a cylindrical metal stem electrically connected and extending lengthwise through and projecting from the opposite ends of said plug, a screw-threaded nut ,-'on one of the projecting ends, and 4a spherical shaped head, constituting an electrode, on the other opposite projecting end' of said stem, and said head lying within and spaced from said electrode of said shell, all substantially as described, and for the sev.- eral purposes specified, l

2. A sparking-plug comprising, in combi.- nation, an electr-ical connected metal tubular shell, exteriorly screwthreaded and at its opposite end-portions open and of different internal diameters joined by a circular running shoulder, and at its larger open endinternally Vscrew-threaded and at. itsl smaller open .end having-a circular radial 'flange pr'ectin inwardly, constituting an elec.-

tro e,` an also having apertures aboutsaidshell, and at one end having an internal clrthe rejecting en ds, and a s hercal sha 1,018,388 y e f 8 iange leading to its interior chamber, a connected and extendin lengthwise through gland exteriorly screw-threaded and screwand projecting from t e eoiposlte ends of mg into said screw-threaded end of said said plug, a screw-thread nut on one of 20 cular running ange or .'ouldei and at its hea ,constituting an electro e, on the o er 'posite and open end a removable land opvosite project' end of said stem,

s ve closely fitting and terminating thereand sai head ying wit and spaced within and projecting therefrom, an insusaid electrode of said shell, all substantially 25 lated cylindrical and tubular plug havingan as described and for the several purposes external running collar l between said specifi internal flange of andthe en of said sleeve In witness whereof, I have hereunto set within said gland, and at one endrtion my hand in the presence of two subscribing extending into and along and sp from witnesses.

the Smauer tubular endrtion of said Shen GEoRGE s. WALKER. and said sleeve of the and and' at its op- Witnesses: posite endortion projecting from said` ALBERT W. BnowN,

gland, a cy drical metal stem electrically i MARION E. BnowN. 

